Solar Windows and Roofs

Passive windows and roofs can be turned into energy generating windows and roofs.


As a general rule, the most successful man in life is the man who has the best information


Richard (Rick) Mills


Feldspars are found in granite type pegmatite rocks which are a mixture of feldspar minerals together with quartz and mica.


There are three types of feldspar minerals:

  • Sodium feldspar or Na-spar
  • Potassium feldspar or K-spar - Deposits of high quality K-spar that can be economically extracted are extremely rare.
  • Calcium feldspar or Ca-feldspar

High quality feldspar has to offer low iron oxide and high alkali oxide content per unit of alumina. High concentrations of alumina and alkalis (calcium (Ca2O), potassium (K2O) and sodium (Na2O)) oxides, together with low levels of coloring trace elements such as iron oxide (Fe2O3) and titanium (Ti02) are essential for whiteness and translucency.


Alumina (Al2O3) adds hardness, durability and resistance to chemical corrosion. The alkalis in feldspar act as a flux. Fluxes enhance melting by forming a glassy matrix that bonds the other components of the system together at an early stage in the firing process reducing process energy costs.


The ceramic and glass industries are the major consumers of feldspar and account for 95% of the total consumption.




Ceramics are non metallic, inorganic solids commonly defined as inorganic crystalline materials such as earthenware, stoneware, and porcelain.


“A ceramicist must put together a mixture of materials which, once fired, will produce a ceramic material of the right molecular composition for the final product. To achieve this, they must have knowledge of the chemical make-up of each ingredient, along with an understanding of the thermal requirements of the composition. The original components no longer exist, but are intimately fused together to form a new and different material: A ceramic body with the required shape and strength for the end use application. Feldspar strengthens and ensures the durability of fired bodies” The Quartz Corp.


Most of the products we use on a daily basis are made with feldspar: glass for drinking, protection and packaging, fiberglass for insulation, floor tiles,  shower and wash basins and the tableware from which we eat.


But ceramics are also heavily used in many diverse applications such as; nuclear energy production, bricks, statuettes, pipes, building materials, superconductors, orbital heat entry shields, industrial heating elements, glazings, solar thermal energy absorbers, and ultrasonic transducers.


The chemical and petrochemical sector uses ceramic products in the manufacturing of thermocouple protection tubes, pumping components and rotary seals. In the coatings sector ceramics are used on engine components, cutting tools, industrial wear parts, biomedical implants, anti-reflection, optical and self-cleaning coatings for building materials.


Rising government expenditure on infrastructure development and anticipated growth in the U.S. industrial sector is expected to have have a positive impact on the overall market for the next seven years.


According to a new report by Grand View Research the global ceramics market is expected to reach US$287.06 billion by 2022.




About 110 pounds of feldspar are used to produce one ton of container glass and 100 pounds are required to produce one ton of flat glass.


The Freedonia Group


The North American flat glass market for 2015 was valued over US$6 billion.


Increasing adoption of glass in the construction and automobile industry will drive the global flat glass market size.


Tempered Glass


K-spar and Na-spar are increasingly being used in the fabrication of tempered glass and solar panels.


Tempered glass, or as it’s more commonly known safety glass, is used in place of other glass products where increased strength and safety is required. Tempered glass is up to six times the strength of normal plate glass. Because the glass is so strong it can effectively resist wind pressure and impact.


Safety glass also has a unique fracture pattern. Called ‘dicing’ it shatters into small pieces rather than creating long and razor sharp shards.


Fully tempered glass is used in applications like doors, side lights, shower and tub enclosures, interior partitions, storm doors, patio-door assemblies, and escalator and stairway balustrades. As a glazing product it is used in windows and in spandrel areas (for wind pressure, impact and thermal stress resistance). Special building applications include sloped glazing, racquetball courts, skylights and solar panels.


The domestic motor vehicle industry employs tempered glass as side and rear windows in automobiles, trucks, and multi-purpose vehicles.


Manufacturing industries use tempered glass in refrigerators, furniture, ovens, shelving, and fireplace screens.


“The Global Tempered Glass Market is poised to grow at a CAGR of around 7.7% over the next decade to reach approximately US$71.5 billion by 2025.”  Tempered Glass Market Analysis By Application (Automotive, Construction,) And Segment Forecasts To 2022


Solar Glass


“The global PV industry has developed steadily in recent years - between 2010 and 2015 the global cumulative PV installed capacity registered a CAGR of 41.6%, which brought rapid growth of PV glass consumption. In 2015, the global PV glass consumption attained 580 million square meters, up 44.4% yoy. The CAGR is expected to stay above 20% between 2016 to 2020.” Global and China Photovoltaic Glass Industry Report, 2016-2020


Photovoltaic glass (PV glass) is directly used for solar PV power generation and solar thermal power generation system components and plays a role in transmission and sunlight control, or conduction. To ensure high solar energy transmittance, glass with low iron oxide is typically used.



The solar industry’s current demand for glass is less than 3% of the overall market. However, with the huge growth in the solar industry this situation is changing.


According to Greentech Media for the first time ever, U.S. solar ranked as the number one source of new electric generating capacity, growth of nonresidential installations surpassed residential solar for the first time since 2011 and the U.S. solar market nearly doubled its annual record, topping out at 14,625 megawatts of solar PV installed in 2016.


The average price of a solar module was $76.67/watt in 1977, $4 per watt in 2008, $0.74/watt in 2013 and, according to PVinsights $0.49/watt on July 15, 2016.


Oxford University researchers say solar’s share of global electricity will grow from roughly 1.5% today, to as much as 20% by 2027.


For the first time, more solar systems came online in 2016 than natural gas power plants - the top source of electricity in the US in 2015 - as measured in megawatts. Solar capacity is irrefutably going up, and prices are collapsing.


“U.S. demand for high-performance flat glass products is forecast to rise 4.4% per year to 910 million ft2 in 2017, valued at nearly $9.2 billion. Consumption of solar control glass products is largely concentrated in the architectural market and will benefit from rapid increases in new building construction.


The security and safety glass segment holds the largest share of high-performance flat glass sales in value terms, accounting for over two-thirds of the total in 2012. Consumption of security and safety glass is projected to grow at an above average pace through 2017.” Solar Control Glass Expected to Help Drive U.S. Flat Glass Market


“Concentrating Solar Power (CSP) has moved from the trial stage to the early adopter stage. Markets at $510 million in 2014 are expected to reach $4.7 billion by 2021. Growth is expected to achieve 15% of total low iron glass production in 2021, i.e. the same level as all automotive glass.” Low Iron Glass: Market Shares, Strategies, and Forecasts, Worldwide, 2015 to 2021


Solar windows


Rooftops are the obvious place for a solar panel because they receive more direct sunlight than a building’s façade. But because of their sheer square footage certain building façades can be tapped as sources of solar-power generation. 


Experts say that, depending on the number of south-facing windows and the building's location, solar panel tempered glass technology could provide from 20% to 30% of a buildings energy needs.


Tempered Solar Glass Tiles


The tiles have embedded solar photovoltaic cells between multi-layered tempered glass.



Cheaper than a conventional roof? So says Tesla’s CEO Elon Musk. Musk has recently made the claim Solarcity’s new solar roof tiles will be cheaper than a conventional roof even without adding in the cost of electricity saved.


They’re made of tempered glass, weigh as little as a fifth of current products,  are virtually indistinguishable from high-end roofing products and they transform sunlight into power for your home and of course, your electric car. 



“The Global market for feldspar is projected to reach 25.6 million tonnes by 2022, driven primarily by the recovery in the world construction industry and rising demand for glass and ceramic products. Also poised to benefit market growth is steady industrialization in developing markets and the ensuing rise in the use of feldspar in industrial applications where the mineral’s alumina and alkali content are valuable features. The growing global focus on renewable energy especially solar energy is expected to spur consumption of feldspar in the production of solar glass used in solar cells.” Global Industry Analysts. Inc., The Global Feldspar Market




Imery’s Performance Metals closed its U.S. feldspar production site in December 2013. The company had previously been supplying 50% of U.S. production. Imery’s lost production, the highest quality K-spar, is being made up by imports of Spanish feldspar.


India last year received a request from representatives of its ceramics industry to ban exports of feldspar and quartz.


In China, prices for feldspar used in ceramics has been rising steadily and are now up as much as 30% over 2008 levels.


There is one U.S. feldspar supplier left, and their focus is on pottery, not solar. There is no high quality K-spar or Na-spar production in the U.S. or Canada (except for a privately owned mine in S.W. Quebec, it’s product is used for crowns and implants), for solar glass or solar roof tile applications.


Nature, and business, abhor a vacuum.


Richard (Rick) Mills


Richard lives with his family on a 160 acre ranch in northern British Columbia. He invests in the resource and biotechnology/pharmaceutical sectors and is the owner of


This document is not and should not be construed as an offer to sell or the solicitation of an offer to purchase or subscribe for any investment.

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